The invention relates to a driver's cab supporting structure for a commercial vehicle having a safety cell, particularly a heavy commercial vehicle.
European patent document EP 0 718 176 B1 discloses a supporting structure for a driver's cab of a commercial vehicle, which includes the doors and is designed as a safety cell for driver and passenger. The driver's cab is reinforced and stiffened by a stiffening rib that is integral to the wall. Such all-round stiffening of the driver's cab is provided in three height positions: in the region of the driver's cab floor, in the region of the transition to the roof and in the railing region below the windshield. External forces acting in the horizontal direction can be counteracted in a specific manner in the three zones. The driver's cab is less deformed than in previously known solutions. To stiffen it, the front wall, rear wall and side walls of the driver's cab are reinforced by a profiling, using a pressing technique, of their inside and outside sheet-metal pressed parts, and by partial further reinforcement of the stiffening profile regions with additional sheet-metal pressed profiles. The reinforcements are of encircling design in the three height positions and in vertical planes in the region of the A- or hinge pillars, the B- or lock pillars, the C-pillars and at least one pillar in the rear wall.
German patent document DE 2853621A and U.S. Pat. No. 6,520,565, disclose a generic driver's cab supporting structure for a commercial vehicle, in which a safety cell is arranged in a driver's cab with a front region and a rear side facing a loading region. A seating region is surrounded by a stiff safety cell to which a deformation region for absorbing deformation energy is connected between seating region and loading region.
European patent document EP 1164073A discloses a driver's cab supporting structure, in which a cage-like safety cell is provided which maintains its original shape in the case of an impact.
Furthermore, European patent document EP 0685381A discloses a driver's cab supporting structure, in which a roll bar is used part of a cage-like driver's cab structure.
One object of the present invention to provide an improved driver's cab supporting structure for a commercial vehicle having a safety cell, particularly for a heavy commercial vehicle.
This and other objects and advantages are achieved by the driver's cab supporting structure according to the invention, in which a seating region is surrounded by a stiff, cage-like safety cell to which a deformation region for absorbing deformation energy is connected between seating region and loading region. Part of a longitudinal member behind the seating region is designed as a deformation region, so that a further compression volume can be made available. This design is suitable particularly for a short driver's cab without a living and sleeping region, in which a substantial compression volume is not available in the driver's cab itself. The deformation volume is preferably integrated in the longitudinal member behind the seating region and a support against a vehicle frame. The safety cell is particularly stiff, while the deformation region is especially pliable, so that the driver's cab is stiffened locally and is weakened in a specific manner locally, so as to provide a deformation zone.
The effect which can therefore be achieved is that, in the event of a rear-end collision (for example of truck against truck), in which a driver's cab is compressed until stiff structures of the colliding truck can be effectively supported, an adequate survival space for a driver in the colliding truck is maintained. This is advantageous particularly in the case of heavy commercial vehicles of several tens of tons, since, in a rear-end collision, kinetic energy can scarcely be supported via the driver's cab. An effective support therefore generally takes place on a frame of the above truck or its trailer. A superstructure penetrates the colliding driver's cab in accordance with a rear overhang and the elasticity of the front structure of the colliding commercial vehicle. The differing stiffness of the driver's cab according to the invention makes available a necessary compression volume behind the seating region, while the seating region is protected by the stiff safety cell. The safety cell can be displaced in essentially undeformed form while the kinetic energy is converted in the compression volume of the deformation region into deformation energy. Preferably, at least the driver's seat is surrounded by the stiff safety cell.
If the safety cell is displaceable relative to the vehicle frame, even if the protruding superstructure of the truck traveling in front dips inward, the safety cell can remain intact and a survival space can be maintained. If the driver's cab or the longitudinal member is affected by an impact, as a reaction the safety cell can move relative to the vehicle frame, and can conduct energy to the deformation region. The safety cell remains intact.
If the deformation region comprises part of the driver's cab, then, in the case of a driver's cab of sufficient size, preferably with a living and sleeping region behind the seating region, a large compression volume can be achieved. The driver's cab is preferably designed as a deformation region in the living or sleeping region arranged behind the seating region.
If the longitudinal member has an absorbing region which is mounted upstream of the safety cell, in the case of an accident an impact can be prevented from acting directly on the safety cell and, instead, the impact acts on the deformation region of the longitudinal member and, if appropriate, on an additional deformation region in front of the driver's cab.
If the longitudinal member is of L-shaped design, with a first arm of the longitudinal member being placed as an absorbing region in front of the safety cell and the safety cell being mounted on a second arm, a front region of the driver's cab can effectively be prevented from sustaining an intrusion. Impact energy can be diverted to the deformation region or regions.
If the safety cell is cuboidal, with cuboid edges being formed by roll bars, the safety cell favorably encapsulates the driver's and/or passenger's seat, and makes it easier to rescue occupants in the event of an accident.
If the safety cell is formed by separate driver's and passenger's cells, then, in the case of an impact on one side, the safety of the less affected cell can be increased, because the two cells are essentially decoupled or can be decoupled from each other in the event of an impact, and are at least movable in relation to each other. A connection between driver's cell and passenger's cell is expediently pliable or releasable, so that, in the event of deformation, the safety cells can be released from each other and can react independently of each other.
If an additional deformation region is mounted upstream of the safety cell, an additional compression volume can be provided and the safety of the occupants can be increased.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.